Quick Answer
Okay so here's the quick version. Your solar panels aren't producing as much electricity as they used to. Often, it’s just dirt, leaves, or bird droppings causing uneven shading and creating a 'hot spot' where part of the panel overheats and reduces the overall system's output. First, try giving them a good, safe cleaning. If that doesn't fix it, you might have a faulty panel or a failed component called a bypass diode. A simple cleaning you can do yourself for under $50. But if you need a professional to troubleshoot or work on the roof, you're looking at $200-$500 just for the inspection visit.
Common Symptoms
Possible Causes
Step-by-Step Diagnosis
Step 1
Visual Inspection - Use binoculars to check panels from the ground for debris, bird droppings, or discoloration (hot spots). Note any new shadows from trees or structures.
Step 2
Check Your Inverter App - Analyze the production data. Look for discrepancies between different strings or panels to isolate the problem area.
Step 3
The Cleaning Test - If panels are dirty and it's safe to do so, clean them with a soft brush and soapy water. Monitor production afterward to see if it improves.
Step 4
Professional Thermal Imaging - A pro uses a thermal camera to definitively identify hot spots, which appear significantly hotter than the surrounding panel areas.
Step 5
Professional Electrical Testing - A technician will safely disconnect the suspect panel and use a multimeter to test its voltage and current against the manufacturer's specifications to confirm a fault.
DIY vs Professional Costs
| Repair Type | DIY Cost | Professional Cost | Time Required |
|---|---|---|---|
Panel Cleaning (dirt, leaves, etc.) | $0-50 | $150-500 | 1-3 hours |
Trimming Small Trees/Bushes | $0-100 | $200-1500+ | 1-8+ hours |
Diagnostic Visit (with thermal scan) | N/A | $200-500 | 1-2 hours |
Bypass Diode Replacement | N/A | $250-700 | 2-4 hours |
Single Panel Replacement | N/A | $400-1000+ | 2-4 hours |
When to Call a Professional Solar
- You've cleaned the panels but the power output is still significantly lower than expected.
- You can see visible physical damage to a panel, such as cracks, burn marks, or delamination (peeling layers).
- Your inverter is displaying persistent error codes related to low production or string faults.
- You are not comfortable or it is not safe for you to get on your roof for inspection and cleaning.
- You suspect an electrical issue like a failed bypass diode or need a definitive diagnosis with a thermal camera.
Prevention Tips
- Regular Cleaning: Clean panels 1-4 times per year depending on your location to prevent the buildup of dirt and grime that causes shading.
- Proactive Tree Trimming: Keep an eye on nearby trees and vegetation and trim them back before they start casting shadows on your array.
- Install Critter Guards: Use wire mesh guards around your panel array to prevent birds and squirrels from nesting underneath, which reduces debris and fire risk.
- Regular System Monitoring: Check your inverter's monitoring app weekly to catch any sudden drops in energy production immediately.
- Schedule Professional Inspections: Have a pro inspect your system every couple of years to catch potential issues like microcracks or failing components before they become major problems.
Frequently Asked Questions
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